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Pectolytic Enzymes of the Industrial Fungus Aspergillus kawachii

  • Vita, Carolina Elena;Esquivel, Juan Carlos Contreras;Voget, Claudio Enrique
    • Food Science and Biotechnology
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    • v.18 no.6
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    • pp.1365-1370
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    • 2009
  • Aspergillus kawachii extracellular pectinases were screened in liquid cultures with different carbon sources. The fungus grown on citrus pectin or lemon pomace produced at least one of these inducible pectinases: acidic polygalacturonase, pectin lyase, pectin methylesterase, $\alpha$-L-arabinofuranosidase, $\alpha$-1,5-endoarabinase, $\beta$-D-galactosidase/exogalactanase, and $\beta$-1,4-endogalactanase. The lemon-pomace filtrates also contained significant $\alpha$-L-rhamnosidase and $\beta$-D-fucosidase activities. Most of the screened pectinases were active at pH 2.0-2.5, indicating that the A. kawachii enzymes were acidophilic. Under the culture conditions employed we could not detect enzymatic degradation of soybean rhamnogalacturonan. The A. kawachii pectinase-production-related regulatory phenomena of induction-repression resemble those described for other Aspergillus sp.

Cloning, Sequencing and Expression of the Gene Encoding a Thermostable β-Xylosidase from Paenibacillus sp. DG-22 (Paenibacillus sp. DG-22로부터 열에 안정한 β-xylosidase를 암호화하는 유전자의 클로닝, 염기서열결정 및 발현)

  • Lee, Tae-Hyeong;Lee, Yong-Eok
    • Journal of Life Science
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    • v.17 no.9 s.89
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    • pp.1197-1203
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    • 2007
  • A genomic DNA library of the bacterium Paenibacillus sp. DG-22 was constructed and the ${\beta}-xylosi-dase-positive$ clones were identified using the fluorogenic substrate $4-methylumbelliferyl-{\beta}-D-xylopyr-anoside$ $({\beta}MUX)$. A recombinant plasmid was isolated from the clone and 4.3-kb inserted DNA was sequenced. The ${\beta}-xylosidase$ gene (xylA) was comprised of a 2,106 bp open reading frame (ORF) en-coding 701 amino acids with a molecular weight of 78,710 dalton and a pI of 5.0. The deduced amino acid sequence of the xylA gene product had significant similarity with ${\beta}-xylosidases$ classified into family 52 of glycosyl hydrolases. The xylA gene was subcloned into the pQE60 expression vector to fuse with six histidine-tag. The recombinant ${\beta}-xylosidase$ $(XylA-H_6)$ was purified to homogeneity by heat-treatment and immobilized metal affinity chromatography. The pH and temperature optima of the $XylA-H_6$ enzyme were pH 5.5-6.0 and $60^{\circ}C$, respectively.

The Physiological and Ecological Comparisons between Warm (Pleuromamma sp.) and Cold Water Copepod Species (Neocalanus plumchrus) in the Northwestern Pacific Ocean Using Lipid Contents and Compositions (북서태평양에서 난수성(Pleuromamma sp.)과 냉수성(Neocalanus plumchrus) 요각류의 지방 함량 및 구성 분석을 통한 생리/생태 비교)

  • Ko, Ah-Ra;Ju, Se-Jong;Lee, Chang-Rae
    • Ocean and Polar Research
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    • v.31 no.1
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    • pp.121-131
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    • 2009
  • In an effort to better understand the physiological and ecological differences between warm and cold water copepod species in Korean waters using lipid contents and compositions, two species of copepods (Pleuromamma sp. as a warm water species and Neocalanus plumchrus as a cold water species) were collected from the Northwest Pacific and East Sea/Sea of Japan, respectively. The cold water species showed two fold higher lipid contents than the warm water species (11% vs. 5% of dry weight). Wax esters, known as one of the major storage lipid classes, were found to be the dominant lipid class (accounting for 64% of total lipids) in the cold water species, whereas, in the warm water species, phospholipids, which are known as membrane components, were the dominant lipid class (accounting for 43% of total lipids),with a trace amount of the storage lipids as a form of triacylglycerols (${\leq}1%$ of total lipids). With regard to the fatty acid compositions, saturated fatty acids (SAFA), especially 16:0 (about 30% of total fatty acids), were most abundant in the warm water species, whereas the polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic acid (EPA : 20:5(n-3)) (${\geq}16%$ of total fatty acids), were most abundant in the cold water species. Among the neutral fraction of lipids, phytol, originating from the side chain of chlorophyll and indicative of active feeding on phytoplankton, was detected only in the warm water species. Significant quantities of fatty alcohols were detected in cold water species, particularly long-chain monounsaturated fatty alcohols (i.e. 20:1(n-9) and 22:1(n-11)), which are well known to abound in cold water herbivorous copepods. However, only trace amounts of short-chain fatty alcohols were detected in the warm water species. Twelve different kinds of sterols were detected in these copepod species, with cholest-5-en-$3{\beta}$-ol (cholesterol) and cholesta-5, 24-dien-$3{\beta}$-ol (desmosterol) dominating in cold and warm water species, respectively. In addition, for the warm water species (Pleuromamma sp.), we assessed the latitudinal gradients of lipid contents and compositions using samples from three different latitudinal regions (Philippine EEZ, Japan EEZ, and the East China Sea). Although no latitudinal gradients of lipid contents were detected, the lipid compositions, particularly dietary fatty acid markers, varied significantly with the latitude. The findings of this study confirm that the distribution of lipid contents and compositions in copepods may not only indicate their nutritional condition and diet history, but may also provide insights into their living strategies under different environmental conditions (i.e., water temperature, food availability).

Antifungal Activity and Plant Growth Promotion by Rhizobacteria Inhibiting Growth of Plant Pathogenic Fungi (식물병원성 진균을 억제하는 근권세균의 항진균능과 식물생장촉진능)

  • Jung, Taeck-Kyung;Kim, Ji-Hyun;Song, Hong-Gyu
    • Korean Journal of Microbiology
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    • v.48 no.1
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    • pp.16-21
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    • 2012
  • Since many pesticides cause various health and environmental problems, alternative measures to replace them are needed, and the bacteria producing the antifungal substances can be one of them. In this study, several rhizobacteria were isolated and their antifungal activities against some important plant pathogenic fungi were examined. Pseudomonas otitidis TK1 and Paenibacillus peoriae RhAn32 inhibited the growth of Fusarium oxysporum f. sp. niveum and F. oxysporum f. sp. lycopersici by 49.8% and 45.6%, and 45.1% and 48.3%, respectively compared to those of the control. P. peoriae RhAn32 also decreased the growth of F. oxysporum f. sp. raphani by 37.5%. This growth inhibition might be due to the production of antifungal substances, such as siderophore, hydrogen cyanide and chitinase, which were produced by these rhizobacteria. P. otitidis TK1 also produced plant growth hormones indole acetic acid and indole butyric acid at $293.41{\mu}g/mg$ protein and $418.53{\mu}g/mg$ protein, respectively. When P. otitidis TK1 and B. cereus TK2 were inoculated together with F. oxysporum f. sp. lycopersici to the 4 weeks grown tomato seedlings and incubated additional 8 weeks, the stem lengths of tomato increased up to 45.7% and 55.3% and root lengths were raised to 64.9% and 60.8%, respectively than those of the control group. The wet weights increased by 118% and 182%, respectively compared to the control group.

YJI-7 Suppresses ROS Production and Expression of Inflammatory Mediators via Modulation of p38MAPK and JNK Signaling in RAW 264.7 Macrophages

  • Oh, Hye Jin;Magar, Til Bahadur Thapa;Pun, Nirmala Tilija;Lee, Yunji;Kim, Eun Hye;Lee, Eung-Seok;Park, Pil-Hoon
    • Biomolecules & Therapeutics
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    • v.26 no.2
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    • pp.191-200
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    • 2018
  • Chalcone, (2E)-1,3-Diphenylprop-2-en-1-one, and its synthetic derivatives are known to possess anti-oxidative and anti-inflammatory properties. In the present study, we prepared a novel synthetic chalcone compound, (E)-1-(4-hydroxyphenyl)-3-(2-(trifluoromethoxy)phenyl)prop-2-en-1-one name (YJI-7), and investigated its inhibitory effects on endotoxin-stimulated production of reactive oxygen species (ROS) and expression of inflammatory mediators in macrophages. We demonstrated that treatment of RAW 264.7 macrophages with YJI-7 significantly suppressed lipopolysaccharide (LPS)-stimulated ROS production. We also found that YJI-7 substantially decreased NADPH oxidase activity stimulated by LPS, indicating that YJI-7 regulates ROS production via modulation of NADPH oxidase in macrophages. Furthermore, YJI-7 strongly inhibited the expression of a number of inflammatory mediators in a gene-selective manner, suggesting that YJI-7 possesses potent anti-inflammatory properties, as well as anti-oxidative activity. In continuing experiments to investigate the mechanisms that could underlie such biological effects, we revealed that YJI-7 suppressed phosphorylation of p38MAPK and JNK stimulated by LPS, whereas no significant effect on ERK was observed. Furthermore, LPS-stimulated production of ROS, activation of NADPH oxidase and expression of inflammatory mediators were markedly suppressed by treatment with selective inhibitor of p38MAPK (SB203580) and JNK (SP600125). Taken together, these results demonstrated that YJI-7, a novel synthetic chalcone derivative, suppressed LPS-stimulated ROS production via modulation of NADPH oxidase and diminished expression of inflammatory mediators, at least in part, via down-regulation of p38MAPK and JNK signaling in macrophages.

Strategies to Assess Occupational Exposure to Airborne Nanoparticles: Systematic Review and Recommendations

  • Louis Galey;Sabyne Audignon;Patrick Brochard;Maximilien Debia;Aude Lacourt;Pierre Lambert;Olivier Le Bihan;Laurent Martinon;Sebastien Bau;Olivier Witschger;Alain Garrigou
    • Safety and Health at Work
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    • v.14 no.2
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    • pp.163-173
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    • 2023
  • In many industrial sectors, workers are exposed to manufactured or unintentionally emitted airborne nanoparticles (NPs). To develop prevention and enhance knowledge surrounding exposure, it has become crucial to achieve a consensus on how to assess exposure to airborne NPs by inhalation in the workplace. Here, we review the literature presenting recommendations on assessing occupational exposure to NPs. The 23 distinct strategies retained were analyzed in terms of the following points: target NPs, objectives, steps, "measurement strategy" (instruments, physicochemical analysis, and data processing), "contextual information" presented, and "work activity" analysis. The robustness (consistency of information) and practical aspects (detailed methodology) of each strategy were estimated. The objectives and methodological steps varied, as did the measurement techniques. Strategies were essentially based on NPs measurement, but improvements could be made to better account for "contextual information" and "work activity". Based on this review, recommendations for an operational strategy were formulated, integrating the work activity with the measurement to provide a more complete assessment of situations leading to airborne NP exposure. These recommendations can be used with the objective of producing homogeneous exposure data for epidemiological purposes and to help improve prevention strategies.

Isolation of Hydrogen-producing Bacteria from Granular Sludge of an Upflow Anaerobic-Sludge Blanket Reactor

  • Oh, You-Kwan;Park, Mi-So;Seol, Eun-Hee;Lee, Sang-Joon;Park, Sunghoon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.1
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    • pp.54-57
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    • 2003
  • H$_2$-producing bacteria were isolated from anaerobic granular sludge. Out of 72 colonies (36 grown under aerobic conditions and 36 under anaerobic conditions) arbitrarily chosen from the agar plate cultures of a Suspended sludge, 34 colonies (15 under aerobic conditions and 19 under anaerobic conditions) produced H2 under anaerobic conditions. Based on various biochemical tests and microscopic observations, they were classified into 13 groups and tentatively identified as follows: From aerobic isolates, Aeromonar spp. (7 strains), Pseudomonas spp. (3 strains), and Vibrio spp. (5 strains); from anaerobic isolates, Actinomyces spp. (11 Strains), Clostridium 5pp. (7 strains). and Porphyromonas sp. When glucose was used as the carbon substrate, all isolates showed a similar cell density and a H$_2$ production yield in the batch cultivations after 12 h (2.24-2.74 OD at 600 nm and 1.02-1.22 mol H$_2$/mol glucose, respectively). The major fermentation by-products were ethanol and acetate for the aerobic isolates, and ethanol, acetate and propionate for the anaerobic isolates. This study demonstrated that several H$_2$ producers in an anaerobic granular sludge exist En large proportions and their performance in terms of H$_2$ production is quite similar.

Synthesis LiFePO4- poly(sodium 4-styrenesulfonate) composite cathode material for rechargeable lithium battery by hydrothermal method

  • Hiep, Nguyen Van;Wang, Wan Lin;Jin, En Mei;Gu, Hal-Bon
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.137.2-137.2
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    • 2011
  • Poly (sodium 4-styrenesulfonate) (PSS) is ionomer based on polystyrene that is electrical conductivity and isoviscosity. LiFePO4 has been a promising electrode material however its poor conductivity limits practical application. To enhance the electronic conductivity of LiFePO4, in this study we prepared LiFePO4- PSS composite by the hydrothermal method. LiFePO4 was heated at $170^{\circ}C$ for 12h and then different wt% PSS (0%, 2.91%, 4.75%, 7.36%, 10%) are added to LiFePO4 and milled at 300rpm for 10h. And then the obtained powders were subsequently heated at $500^{\circ}C$ for 1h under argon flow. The cathode electrode were made from mixtures of LiFePO4-PSS: SP-270- PVDF in a weighting ratio 75%: 25%:5%. The electrochemical properties of LiFePO4- PSS/Li batteries were analyzed by cyclic voltammetry and charge/discharge tests. LiFePO4-C/Li battery with 4.75 wt% PSS displays discharge capacity of 128 mAh g-1 at room temperature that is considerably higher than pure LiFePO4/Li battery ( 113.48 mAhg-1).

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Nucleotide and protein researches on anaerobic fungi during four decades

  • Chang, Jongsoo;Park, Hyunjin
    • Journal of Animal Science and Technology
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    • v.62 no.2
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    • pp.121-140
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    • 2020
  • Anaerobic fungi habitat in the gastrointestinal tract of foregut fermenters or hindgut fermenters and degrade fibrous plant biomass through the hydrolysis reactions with a wide variety of cellulolytic enzymes and physical penetration through fiber matrix with their rhizoids. To date, seventeen genera have been described in family Neocallimasticaceae, class Neocallimastigomycetes, phylum Neocallimastigomycota and one genus has been described in phylum Neocallimastigomycota. In National Center for Biotechnology Information (NCBI) database (DB), 23,830 nucleotide sequences and 59,512 protein sequences have been deposited and most of them were originated from Piromyces, Neocallimastix and Anaeromyces. Most of protein sequences (44,025) were acquired with PacBio next generation sequencing system. The whole genome sequences of Anaeromyces robustus, Neocallimastix californiae, Pecoramyces ruminantium, Piromyces finnis and Piromyces sp. E2 are available in Joint Genome Institute (JGI) database. According to the results of protein prediction, average Isoelectric points (pIs) were ranged from 5.88 (Anaeromyces) to 6.57 (Piromyces) and average molecular weights were ranged from 38.7 kDa (Orpinomyces) to 56.6 kDa (Piromyces). In Carbohydrate-Active enZYmes (CAZY) database, glycoside hydrolases (36), carbohydrate binding module (11), carbohydrate esterases (8), glycosyltransferase (5) and polysaccharide lyases (3) from anaerobic fungi were registered. During four decades, 1,031 research articles about anaerobic fungi were published and 444 and 719 articles were available in PubMed (PM) and PubMed Central (PMC) DB.

A Study on the Capacity Characteristic of $LiFePO_4$ Cathode for Lithium Polymer Batteries according to kinds of the conductive materials (도전재 종류에 따른 리튬폴리머전지용 $LiFePO_4$ 정극활물질의 용량특성의 변화)

  • Jin, En-Mei;Jin, Bo;Li, Hu;Park, Kyung-Hee;Gu, Hal-Bon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.316-316
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    • 2007
  • 리튬폴리머 전지용 정극활물질인 $LiFePO_4$를 수열법으로 합성하였다. 제조한 정극활물질 $LiFePO_4$는 X-ray 회절분석을 통하여 olivine 구조임을 확인하였다. 전극 제조 시 첨가된 도전재의 종류에 따른 전기화학적 특성변화를 알기 위하여, Acetylene Black, Super-Black, Multi-Walled Carbon Nanotube(MWCNT), SP270을 도전재로 제조된 정극활물질과 PVDF를 결합제로 사용하였다. 셀은 제조된 정극과 고체전해질 $25PVDFLiCIO_4EC_{10}PC_{10}$를 사용하고, 부극은 금속리튬으로 coin 타입의 cell을 조립하여 충방전을 진행하였다. 충방전 진행결과, Multi-Walled Carbon Nanotube(MWCNT)를 도전재로 사용하였을 경우, 초기 방전용량은 94mAh/g, 100cycle 후에는 약 93mAh/g인 기타 도전재를 사용하였을 때보다 안정하고 높은 방전용량을 나타내었다. 이때의 충방전 전류밀도는 0.1mAh/g이고 전압범위 는 2.5~4.3V이었다.

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